In equipment such as portable music players, including CD and MD players, and personal digital assistants, users generally listen to sound using earphones or headphones. The equipment and an earphone are generally connected with a cable.
In this case, a control box used to perform the volume control and operation control of a player (selection of music numbers, switch-on/off, and the like) is usually disposed midway through the cable. The control box is provided with switches. In addition, an earphone body which incorporates wireless communications functions is provided with a switch.
A listener who uses earphones in portable equipment often uses the equipment while jogging or doing some sort of work. If, under these circumstances, the location of the switch is limited to one position of a cable at the time of performing switch operation, such as player control, the listener has to look for the position to operate the switch. This may lack swiftness and make the listener feel operationally cumbersome.
Accordingly, if the cable itself is allowed to have switch functions and easily placed in a conduction state by externally pressurizing the cable, the location of switching operation is not limited. This makes switching operation easy and provides excellent usability.
As such a cable, a cable is available in which two conductive members are vertically and oppositely disposed at a distance from each other, a conductive rubber is arranged between the conductive members within an outer cover, and the two conductive members are brought into contact with and made conductive to each other by external pressurization, so as to switch on the cable (Patent Literature 1).
In addition, a cable is available in which two conductive members covered with a conductive rubber are disposed at a distance from each other within an outer cover, and the two conductive members are brought into contact with and made conductive to each other by external pressurization (Patent Literature 2).
Yet additionally, there is available a cable switch provided with a belt-like first base material, and a second base material which is opposed to this first base material and in which a planar positive electrode is arranged on one side of an inner surface, a negative electrode is arranged on the other side, and a gap for separating and insulating these positive and negative electrodes from each other is formed between the electrodes, wherein substantially rectangular windows disposed at predetermined intervals in a length direction are formed by spacers arranged on the positive and the negative electrodes to make the positive and negative electrodes conductive to each other through the conductor (Patent Literature 3).